If I'm buying something online, there are pros and cons to that. Depending on what it is, it may make me happier. If its a new shirt or something, cool. But it will only really make me happier when I'm conscious of its existence, i.e. when I'm wearing it or doing laundry. All the other times I have to live operating with less consumable funds. I don't know about you, but having money makes me feel a lot better than spending it. I know I could redecorate my entire room in a month filled with stuff I've never seen before, and I would probably like it better than the room I have now, but I think simply knowing that makes me happier, too. If you have an egg, you can prepare it so many different ways, but once you choose it can be impossible to change your mind, depending on what your decision was.
If I bought a new room, essentially, I could be happier, sure, but since it serves no real function other than aesthetic I would also be constantly burdened by the fact that I effectively wasted all of that money. My room is fine now, it doesn't need to change.
So when I'm trying to decide on what to do in any given situation, I think of how I'll look back on it in the future. If I go to a friend's house in the middle of the night just to hang out, one, I'll get a lot less sleep, something I'll need for tomorrow's test, and two, I'll get in trouble for not informing any family of where I was going. But at the same time, in the months and years to come, I won't remember a good night's sleep. I'll remember making those memories. I'm responsible enough not to make terrible decisions, but I am adventurous enough to want to make the memorable ones. I may hate myself the next morning, taking that test, but once its over with I'll smile at the good times.
A lot of my generation, I think, is blinded by "the now". While I do believe (the probably unpopular opinion that) our generation is actually making a positive impact on the world, I do consider our lack of foresight to be a great fault. Too many people around me are trying to have as much fun as possible right now, at the cost of their future well-being, when a lot of mistakes and regret can be avoided altogether.
Life is short, sure, but it doesn't have to be full of drastic 'highs' and 'lows'. If you prepare for the 'low' while you're in your 'high', maybe our society would be a lot happier. Just a thought.